Process of separating oil from sulphonated components thereof



Patented Sept. 9, 1930 UNITED STATES PATENT OFFICE HERMAN HEOKE'L AND WARREN T. REDDISH, OF. CINCINNATI, OHIO, ASSIGNORS TO THE TWITGHELL PROCESS COMPANY, OF ST. BERNARD, OHIO, A CORPORATION OF OHIO PROCESS OF SEPARATING OIL FROM SULPRONATE'D COMPONENTS THEREOF No Drawing.

Our inventionrelates to a certain class of products formed by treating certain oils with sulphuric acid and our invention also relates to the art and process of obtaining the same in a pure state.

The oils embraced within the scope of this invention are those hydrocarbon oils characterized by the presence of certain components susceptible to modification by the action of sulphuric acid and certain components not susceptible. Oils such as petroleum, shale oil and coal tar oil, gilsonitic distillates and many'other fractions or distillates of mineral ,oils or hydrocarbon deposits usually exemplify this characteristic.

Since petroleum is commercially available at present in large quantities, the following disclosure of reagents is made in relation thereto.

When petroleum or fractions thereof, such as lubricating stock, are treated with sulphuric acid, certain components of the 'oil are modified. The theory chemically accepted at present explains this modification as sulphonation, i. e., the sulphuric acid reacts with components of the mineral oil (the unsaturated components, supposedly) to form mineral oil sulphonic acid. The yield of sulphonic acid is higher when the oil is treated with fuming sulphuric acid, so this disclosure is also made in relation to this fuming sulphuric acid treatment.

It is further theory that these mineral oil sulphonic acids can be reacted with metallic substance or compounds such as sodium hydroxide or sodium carbonate, for instance, to produce salts of mineral oil sulphonic acid. Research to date seems to indicate that these assumptions are correct, but in the ensuing description of the invention and the claim, it is to be understood that the procedure and products thereof, as described is the real substance of the invention and that the chemical explanation is merely olfered for the benefit of the skilled in the art.

This above described sulphonating treatment is practiced on a lar e commercial scale in the refining of medicmal white oil and similar products. In this refining operation the sulphonated components are the by- Applieation filed J'anuary 11, 1928, Serial No. 246,083.

or steel pipes or containers. The advantage of treating, shipping or handling these sulphonated components in a neutral state is a continuing one.

' In commercial ractice a mineral oil fraction such as a lubricating stock is treated with fuming sulphuric acid. Two layers are formed. The upper layer is known as the A layer or oil layer and the lower layer as the B layer or sludge layer.

The process of refining the white oil and extracting the sulphonates of the oil layer is described and claimed in United States Patent No. 1,087,888 to Grigori Petrolf, issued February 17, 1914; United States Patent No. 1,233,700 to Grigori Petroif, issued July 17, 1917 United States Patent No. 1,196,274 to Grigori Petrofi', issued August 26, 1916, and a specific process in United States Patent No.

1,286,179 to Robert E. Humphrey, issued November 26, 1918.

Some of the pertinent sulphonic sludge layer acids and salts, and the processes of extracting or making them are described 1n the patents to Robert E. Divine, namely: 1,301,- 662, April22, 1919; 1,301,663, April 22, 1919; 1,303,779; May 13, 1919; 1,319,027, Oct. 14, 1919; 1,330,624, Feb. 2, 1920; 1,438,101, Dec. 5 1922.

"All of these sulphonic acids and derivatives of sulphonic acids are either gummy viscous liquids or solids, and according to chemical theory are characterized by very high molecular weights as compared with benzine sulphonic acid. When certain components of the mineral oil are thus sulphonated with fuming sulphuric acid and primary separation from the oil and/or acid environment is effected by the process of any of the above specified patents or by other known processes certain unsulphonated components are separated along with the sulphonated components and constitute impurities therein.

It is very difiicult to separate the sulpho nates themselves from some of the unsulphenated oil which is entrained and apparently has great affinity for the sulphonates. The oil entrained often comprises between 25 and 50% of the volume of the sulphontes. These sulphonates have the power of emulsifying or rendering oil soluble in water and water mixable liquids and it is coi'lscquently very diflicult to separate the sulphonates and this intimately admixed and strongly adherent entrained oil.

Some success has'been obtained by fractionally distilling this oil oil by steam and also fractional extractions with high proof alcohol (75 )6 and over aqueous solution) have also had considerable success.

But one object of this invention is to provide a process of separating the sulphonated and unsulphonated components of mineral oil which is quick, facile, economical and relatively complete as distinguished from fractional separation.

Another object of the invention is to provide a secondary process of separating the sulphonated and the unsulphonated components of mineral oil which process is adapted to be practiced on the sulphonates of the oil layer and also of the sludge layer, after a primary separation of the sulphonates from their initial environments has been effected.

This invention comprises, forming an alcoholic solution or aqueous alcoholic solution of the sulphonates together with the entrained oil and subjecting said solution to the action of centrifugal force, whereby the sulphonates and alcohol are thrown to the outside and the entrained oil to the center. Any one of the various commercial types of centrifuges is suitable for this process.

Any aqueous alcohol is proper for this process though a 30 to alcohol is deemed at present commercially most expedient.

Since the specific gravity of the oil is less than the alcoholic solution of the sulphonates, the oil rises to the higher delivery tube and the heavier solution of alcohol and sulphona-es is delivered from the lower delivery tu e.

This process can be practiced either upon the sulphonic acids themselves orupon their salts, provided only that the salt in question is soluble in alcohol; as are the sodium, sodium aluminum, ammonium and many other sulphonic acid salts.

The following specific examples are provided in order to show the scope of this invention and to enable the skilled in the art to ractice the same.

0 500 pounds of either the sulphonic acids or salts of same to be freed of their oil content, is added preferably four volumes of 6070% alcohol solution. After complete mixing is effected, the resulting solution is subjected to centrifugal action whereby the oil is removed and the alcoholic solution of either acid or salt is freed from alcohol by distillation and the subsequent recovery of alcohol effected.

In case of removing the oil from the sulphonic acids, the acidity is neutralized with caustic before the removal of alcohol to avoid corrosion of equipment on subsequent operations. A

It is likewise possible in practicing the Petrofi' or Humphrey refining process to separate the sulphonates from the lubricating stock by adding to the lubricating stock containing the sulphonates an aqueous alcoholic solution of strength and quantity sullicient to effect substantially the proportions given in the example above. It is to be noted that not all of the oil goes into solution in the aqueous alcohol but that only a relatively small proportion does. However, the oil and the sulphonated components thereof are separated very effectively, more so, than by either the Petr-off or Humphrey process.

The sludge layer salts or acids are freed from oil in the same manner; also the alum salts of either oil or sludge layer material can be freed from oil by rendering the respective alum salts soluble by treating with caus tic soda or by treating with the sludge layer soda salts to the point of water solubility.

Having described our invention, we claim:

The process of separating mineral oil sulphonates from the mineral oil entrained by said sulphonates, said process, cOmpriSing, forming a homogeneous and relatively perman'ent suspension of said sulphonates and entrained oil in an aqueous alcohol, and separating the mineral oil sulphonates from the entrained oil by centrifugal force.

In witness whereof, we hereunto subscribe our names.

HERMAN HECKEL. WARREN T. REDDISH. 

